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Original question:

AM4372: AM4372 no booting

AM4372: AM437x and CD/DAT3 microSD line

albgarc2014
Genius 3365 points
Part Number: AM4372

Hi TI!!!

Why in the AM437x reference designs some times, the line CD/DAT3 of the microSD is pulled up nd some time is pulled down?
What implications has this?

Thank you very much. 

Best regards. 

  • 0
    TI__Mastermind 42545 points

    Hi Albgarc2014,

    There is no CD/DAT3 signal in the data manual for the AM4372.  Can you be more specific with your question?

    Regards, Bill

  • 0 in reply to Bill Taboada
    Genius 3365 points

    Hi , 

    Thank you very much for your answer,

    I did want to say, the signal in the CD/DAT3 in the SDcard memory. Please check the image, in these both reference design are differents connections for CD/DAT3. Some times pulled up and some time pulled down. 

    My real problem is: I have a custom hardware with AM4372 that not boot from the SD, and I need detect the problem. This is very big problem for me and my company, because we have retained a production for a client for this reason. Please, could you soupport me to detect my problem in my design?  I can open a new thread with more details.  

    Thank yuo very much for any suggestion.

    Best regards.

      

  • 0 in reply to albgarc2014
    TI__Mastermind 42545 points

    Hi albgarc2014,

    The SD card specification provides for two methods of card detection.  The AM437 has a separate card detect input, MMC0_SDCD which is connected to a pin of the SD card cage that is pulled low if a card is inserted.  The SD card specification also allows the card to be detected by looking at the CD/DAT3 pin if that pin is pulled low.  I suspect we included that in the starter kit to test both modes.  When booting from an SD card we expect the MMC0_SDCD to be low to detect a card is present.  How do you have this connected?

    Regards, Bill

  • 0 in reply to Bill Taboada
    Genius 3365 points

    Hi  

    Sincerely, thank you very much for you great help.

    Thank you very much for your clear explanation.


    In my design CD/DAT3 is pulled up.


    Note *************!!!*****************
    I have a significative difference in MMC0_SDCD in comparision with the reference design:


    In the reference design MMC0_SDCD is connected to R25 pin, in my design MMC0_SDCD is connected to N24 pin. In my design R25 pin is pulled down (100K).

    Can these diferences be the reason of the problem of no bootting the system?

    Thank you very much. Best regards

  • 0 in reply to albgarc2014
    Genius 3365 points

    Hi

    Note *************!!!*****************

    I have in SYSBOOT pins resistor of 100K.
    Can be the reason of the problem of no booting the system?

    Thank you very much. Best Regards.

  • 0 in reply to albgarc2014
    TI__Mastermind 42545 points

    Hi albgarc2014,

    We recommend stronger pulling resistors for the SYSBOOT pins.  How do you have the SYSBOOT pins configured?  Can you describe all of the pulling resistors that you have attached?

    Regards, Bill

  • 0 in reply to Bill Taboada
    TI__Mastermind 42545 points

    Hi albgarc2014,

    You should always read the value of the CTRL_STS register.  I will indicate that value of the SYSBOOT pins latched by the AM437.

    Regards, Bill

  • 0 in reply to Bill Taboada
    Genius 3365 points

    Hi
    Sincerely thanyou very much,

    Attached my SYSBOOT pin setting.
    It is possible that I send you in private our schematic? Maybe with a simple checking there are an evident problem for you?

    Thank you very much. Best regards

  • 0 in reply to albgarc2014
    TI__Mastermind 42545 points

    Hi albgarc2014,

    It appears that you are setting the AM437 to boot from the MMC0 interface with a system clock at 24MHz.  We can't accept requests for schematic reviews through E2E, you would have to request that review through a TI FAE.  Can you connect to the device using JTAG?

    Regards, Bill

  • 0 in reply to Bill Taboada
    Genius 3365 points

    Thank you very much for you answer!
    It is a great help!
    Yes, we have the JTAG interface available.
    Sincerely, thank you very much again.
    A happy day for you. Best regards.

  • 0 in reply to albgarc2014
    TI__Mastermind 42545 points

    Hi Albgarc2014,

    Let the device attempt to boot an then connect with JTAG.  You can read the CONTROL_STATUS register to see if the sysboot values have been latched correctly.  Once you have determined if the AM437 is correctly configured for SD card boot, we can begin to try and determine why it is not booting.  Does the SD card that  you are using for boot work correctly in the EVM?

    Regards, Bill

  • 0 in reply to Bill Taboada
    Genius 3365 points

    Hill Bill Taboada!

    We did testing testing with a software for evm, for this reaso our board didn't works. 

    Our software engineer are porting the SW and our design are answering! We haven't finish with the SW, but we has a great advance! And your support was a very important help! Sincerely tahnkyuo very much!!!

    A happy day for you!
    Best Regards!

  • 0 in reply to albgarc2014
    TI__Mastermind 42545 points

    Hi,

    I'm very glad to hear you are making progress.  Please let me know if I can help with other issues.  If you have new questions please start a new thread.  It is easier for us to keep track of the threads if each has a single issue.

    Regards, Bill